The invention relates to a vehicle with a tractor and a heavy load trailer, in particular an articulated vehicle in which an hydraulic load compensation unit is provided between the tractor and trailer vehicle.
The invention is based on the problem of producing a vehicle of the above-mentioned type with which it is possible to transmit trailer loads to the tractor without impairment of maneuverability and in particular road holding properties of the whole vehicle.
For the solution of this problem the invention is characterised in that there is connected to the tractor a connecting bridge which is pivoted along two axes in respect of the tractor, one axis of which is disposed parallel to the transverse axis of the vehicle and the other axis perpendicular to a plane passing through the transverse axis of the vehicle and longitudinal axis of the vehicle and that the connecting bridge is connected to the trailer vehicle via a piston-cylinder arrangement producing a hydraulic load compensation as well as via a pivot connection, the axis of which runs parallel to the transverse axis of the vehicle.
According to the admission of the piston-cylinder arrangement via the connecting bridge which is constructed as a two-armed lever a more or less greater portion of load is transmitted to the tractor. Due to the two axes provided at the connecting place between the connecting bridge and the tractor a full load holding of the tractor and of the trailer vehicle is attained.
If the connection between the tractor and the connecting bridge is effected via a king pin an extremely stable connection is provided which in addition is easily coupled. Additionally to this king pin connection the pivot of which therefore runs perpendicularly to the plane of the vehicle a second pivot again perpendicular thereto must be provided which, for example, is formed on the support plate of the tractor vehicle.
Particularly favorable lifting conditions are obtained when the piston-cylinder arrangement is disposed on the rear end of the connecting bridge. The joint connection between the trailer vehicle and connecting bridge is therefore provided between the piston-cylinder arrangement and the traction side connection and of the connecting bridge.
An important feature of the subject matter of the invention is characterised in that the piston-cylinder arrangement is admitted by the axle load of one of the sets of wheels of the trailer vehicle. The transmission of forces considered, between the trailer vehicle and tractor is effected therefore in dependence on the actual axle load of the set of wheels concerned which generally should be arranged in the area of the trailer side point of contact of the piston-cylinder arrangement.
Any other of the sets of wheels of the trailer vehicle may however also be subjected to the piston-cylinder arrangement. This is always of advantage if the load is distributed unequally on the trailer vehicle. In this case that set of wheels may then be connected to the piston-cylinder arrangement which is most affected by the load.
If on the terrain the traction vehicle does not have the adequate ground holding properties then via an additional switch valve via a motor pump additional pressure can be applied to the piston-cylinder arrangement in order thus to ensure a still higher saddle load whereby an adequate ground holding force for the traction vehicle is obtained. This measure may of course also be effected additionally to the admission via one or several sets of wheels.